Most Home Theater users have experienced a "Ground Loop" at some point, even if they have no idea that's what it's called.  A Ground Loop is garbage voltage which travels between the devices in your system -- over the cable shields of the cables connecting them -- looking for a path back to Ground so that current can flow.  In the process, it can cause havoc with various different parts of your system.  The most common symptom is an annoying "Hum" from your Subwoofer.

Getting rid of a Ground Loop can be a trying experience -- made more so if you are operating in the dark about what's going on.  So in this post, we'll talk about Ground Loops:  What they are, where they come from, and how to squelch them.